Hanna test kit issues...

[Beenalongtime79]

Hey Fellow reefers,

I have a few issues with these new hanna spectrophotometer test kits that I received.

http://premiumaquatics.com/store/mer...Category_Code=

http://premiumaquatics.com/store/mer...Category_Code=

Both test kits don't correlate very well with my salifert kits.

Tank water test:

Calcium: Salifert-480ppm
Hanna-668ppm (based on dilution of tank water by 1 volume)
original reading of 334, so I just multiplied by 2

Alkalinity: Salifert-8 dkh
Hanna-7.3dkh

Fresh saltwater mix (SG-1.021)

Calcium: Salifert-320ppm
Hanna-413ppm

So the alkalinity isn't that far off... it is testing approximately 0.7 below the salifert kit with multiple sample runs so fairly precise, although maybe not accurate. As long as I make the appropriate correction, I think I can use it.

However, the calcium is all over the place! I will probably keep the alkalinity kit, but am thinking of returning the calcium. I just can't trust it. What do you guys think? Any suggestions? Should I have premiumaquatics send me another one or should I just go with my trusty salifert kit? Could I have a bum hanna calcium kit or could my calcium actually be that high without massive precipitation of calcium carbonate?

Cheers,
John

 

[scuzy]

My hanna alk is pretty accurate and i heard the calcium is no good.

 

[Blueline12]

There is a huge thread about the Hanna Calcium checker where even Hanna got involved. Hanna has a video on their website about how to use it.

The key to the Calcium checker is EXACTLY precise measurements of the liquids. Also when adding the DI water (DI is a must for this to work properly) you have to fill the DI to the water line where the lower end of the water "meniscus" is at the exact line on the test tube.

I'll try to find the link to the thread.

Nick

 

[Blueline12]

http://www.reefcentral.com/forums/showthread.php?t=2050181

 

[Jeremy B.]

There is a huge thread about the Hanna Calcium checker where even Hanna got involved. Hanna has a video on their website about how to use it.

The key to the Calcium checker is EXACTLY precise measurements of the liquids. Also when adding the DI water (DI is a must for this to work properly) you have to fill the DI to the water line where the lower end of the water "meniscus" is at the exact line on the test tube.

I'll try to find the link to the thread.

Nick

Bingo! The calcium test kit works great as long as you are extremely precise and thorough (and have the time to do so). For some it's just easier to use a Salifert kit for calcium and fly through it.

 

[Beenalongtime79]

Yeah, I will stick with salifert for calcium. I really like the hanna alk kit though!

Even using a 10 cc syringe and putting very precise amounts of fluid in the cuvette, measurements would vary by about 40 ppm between two serial measurements.

Cheers,
John